Method for producing refractory bodies



Patented Nov. 1, 1932 PATENT OFFICE i ARTHUR SPRENGER, OFIBERLIN-KARLSHORST, GERMANY METHOD FOR PRODUCING REFRACTORY BODIES NoDrawing. Application filed July 6,1931, Serial No. 549,124, and inGermany October 10, 1927.

This invention relates to a method for producing refractory bodies, suchas stones, blocks, plates and the like. The bodies according to theinvention are produced from 5 granular material or from material inlumps, and they are moulded after mixing with a bond and subsequentlyburned.

According to the invention chromium iron-magnesia-compounds, orchromite, magbinding of molten masses in granulated condition,containing as chief constituent magnesia or alumina or both substances.The base substance is for example mixed with the cromite or also withother substances containing chromium oxide formed into moulded bodies,preferably by pressing and the like, after which these bodies are burnedat such temperatures, that softening of the bond,chromium-iron-magnesium compounds, chromite, magnesite or the like,occurs.

Masses or grains produced in the melting process, which contains as mainconstituent magnesia, alumina or both substances, if necessary alsochromium oxide and silicic acid possess Very valuable properties, but,when worked with the usual bonds to moulded bodies in granulated stateor as lumps, they possess, owing to the bond, properties which areinferior to those of the base mass. I

According to the invention grains or lumps are preferably employed asbase mass, which are produced by a melting process and possess such acomposition, that the quantity of silicic acid present is less than thatrequired for the monomolecular saturation of the.

alumina, that magnesia is at least sufficient to monomolecularlysaturate the excess of alumina and a portion of the'chromium 0xide. Thisproportion is only calculated. Thus preferably chromium oxide and.magnesia, calculated in mols, must amount to age of silicic acid mustbelittle,particularly in presence of lime.

The bonds to be utilized according to the invention, such aschromiumdron-magneSia compounds, chromite, magncsite and the like,

maybe used in smaller quantities (about nesite or mixtures of these infinest state are, employed as binding substances, i. e. for the morethan 50% of the mass and the percent-" 210%), as already thesequantities are as a ruleamply sufficient for the binding. For exampleabout 6% of chromite Worked u as paste is used. The already mentioned cromite and magnesite or also mixtures of spinels containing chromium andmagnesia may I be mentioned in the first place as chromiumiron magnesiacompounds.

As regards selection ofthe bond or of the mixture of the bonds, theemployment of the on material to be produced is decisive; if to beemployed in basic furnaces M90 or masses witlii a high MgO percentageare preferably use As the binding effect of the above mendo.

tioned substances becomes effective generally only at highertemperatures, it may be necessary to add, for the adhesion of the stonesprior to the burning, organic agglutinants, such as glue or other highlymolecular compounds or inorganic agglutinants, such as magnesiumhydroxide or glyceroboric acid. Such inorganic agglutinants areespecially suitable for this purpose which, at the burning of thestones, evaporate more or less. L1

The moulding is effected in the usual manner by hand or mechanically,and also the burning is carried out in the kilns commonly used for theproduction of refractory products. The excellent properties of thesev-Bfl eral bodies are shown by the results of tests for softeningunder load. a

Granular base mass, produced in the'melting process and bydisintegration of the prod not from smelting, containing silicic acid insmaller quantity than suflic-ient for the monomolecular saturation ofthe alumina, and magnesia in such quantity that the alumina and at leasta portion of the chromium oxide appears monomolecularly saturated, boundwith:

(a) waterglass shows a commencement of the softeningunder load at 1330and less, (b) kaolin a commencement of the softening under load at1370", f (0) (according to the invention) chromium ore at commencementof the softening under load at 1590.

Theexperiments have been carried through at uniform loading of 2 kg. persq. cm.

grated base mass produced in the smelting process, in which mass thepercentage of silicic acid is less. than necessary for the monomolecularsaturation of the alumina, that of magnesia is at least suflicient tomonomolecular saturation of the alumina, thatof magnesia is at leastsutficient to -monolecularly saturate the excess in alumina and aportion ofthe chromium oxide, small quantities of chromium ironmagnesium compounds in fine condition, moulding the mixture and burningthe bodies.

3. A method of producing refractory bodies, such as stones, blocks,plates and the like, from masses produced in the smelting process,consisting in admixing to molten masses containing as main constituentsmagnesia and alumina in granulated state small quantities of chromite infine condition, moulding the mixture and burning the bodies.

4. A method of producing refractory bodies, such as stones, blocks,plates and the like, from masses produced inthe smelting process,consisting in admixing to molten process, consisting in admixin massescontaining as main constituents mag.- nesia and alumina in granulatedstate small quantities of magnesia in fine condition, moulding themixture and burning the bodies.

5. A. method of producing refractory bodies, such as stones, blocks,plates and the like, from masses produced in the smelting to moltenmasses containing as main constituents magnesia and alumina ingranulated state small quantities of chromium iron magnesium compoundsin fine form and substances which atlow temperatures have an adhesiveefie'ct,

6. A method of, producing refractory bodies, such as stones, blocks,plates and the like, from masses-produced in the smelting process,consisting in admixing in molten like, from masses produced in thesmelting process, consisting in admixing to molten masses containing asmain constituents magnesiaand alumina in granulated state smallquantities of chromium-iron-magnesia compounds in fine state in mouldingthe mixture and in burning the bodies at such temperatures thatsoftening of the bond occurs.

In testimony whereof I aflix my signature.

ARTHUR SPRENGER.

, moulding the mixture and burning the bodies.

masses containing as main constituents magnesia and alumina ingranulated state small quantities of chromium-iron-magnesia compounds infine state and substances which at low temperatures have an adhesiveeffect and evaporate during the burning, moulding the mixture andburning the bodies.

7. A method of producingrefractory bodies, such as stones, blocks,plates and the I v3. EERTHFHCATEDF eemeetmN.

Patent No esezee.

ARTHUR *SPRENGERQ It is hereby certifiefl that error appeare in theprihtefl epeeiiieatieh {If the above numbered patent requiringeorreetienes ioiiewe: Page 2, lines 18 mm, claim 2, strike out the words"that of magnesia is at ileest sufficient to monemoiecuiar saturation ofthe aiumina,"; and line 41, eiaim 4, tor "magnesia read 'v'magnesite";and that the said Letters Patent shouid he read with these correctionstherein that the same may conform to Office,

Signed and sealed this 27th day of December, A. 0.. H932.

(Seal) Acting Co ini s s lonerhf Pateiits.

November ll, am.

the record at the casein the. Patent

